Transmission or oil leak after change of radiator ?

So i just changed the radiator in a friends car and then i drove it around to pull coolant through the system and it worked fine....then i left it sitting for about 2 hours then was driving over to her house drove about 2-3 miles with the windows down then decided to try the AC....about 10 seconds after smoke started to come out of the hood and into the car from the vent.....so i pulled over and either transmission fluid or oil was sprayed all over the underside of the hood and the engine...and there was a small tear in one of the little hoses from the radiator that this stuff was spilling out of...so i guess i just wanna know why this happened and if its gonna be an easy fix....please help!!
Transmission or oil leak after change of radiator ?
It depends what color the fluid was. Transmission fluid would be red, oil would be golden or black color. Either way just from what you've stated it would be a place to start your search for the problem at the radiator. You might have stripped a fitting or nicked a hose while reinstalling the new radiator - as the radiator also houses a transmission cooler line as well as an oil cooler line in some newer model vehicles.

The hoses are available at any automotive parts store and shouldn't be too difficult to replace the ruptured hose/hoses. When replacing the damaged hose make sure it's properly secure, not rubbing against any engine parts or kinked at a weird angle so it doesn't fail again.